trigger Date1 on Employee__c (after update,after insert) {
 PUBLIC List<DATE> D;
 PUBLIC List<Decimal> Month;
 PUBLIC List<String> MonthS;
 Public List<Employee__c> emList = [Select Birth_Date__c from Employee__c];
 if(emList.Size()>0){
 system.debug('EmList Check' + emList);  
 for(Employee__c em : emList){
  D.add(em.Birth_Date__c);
 }
 }
 for(Integer i=0;i<=D.Size();i++){
   Month.add(D[i].month());
   MonthS.add(D[i].format());
   System.debug('Months Check' + MonthS);
  }
}